<!--kX Getting Started Guide - Fixing the Bass  problem in 4.1 Setup-->


  <p><font face="arial">This section of the guide will show you how to
      fix the reduced or &quot;washed out&quot; bass when using a 4.1 speaker
      setup, where there is a crossover in the subwoofer (sub takes low end of
      stereo or quadraphonic audio signal).</font></p>
  <p><font face="arial">Note:If you use a 5.1 speaker setup, which requires 6
      connections, then you do not need to read this.</font></p>
  <font face="arial">
  <p>Before I begin to show you how to fix the bass problem, I will first explain
    why it occurs. </p>
  <p>Take a simple waveform&hellip;<br>
  <img src="pic/phase-wave1.gif" width="100" height="100"> </p>
  </font>
  <p><font face="arial">&hellip;and then invert its phase<br>
  <img src="pic/phase-wave2.gif" width="100" height="100"> </font></p>
  <font face="arial"><p>You can clearly see that these two waveforms are opposite to each other.
    Now what happens when these two are added together?<br>
    <img src="pic/phase-wave1.gif" width="100" height="100"><h1>+<br>
      <img src="pic/phase-wave2.gif" width="100" height="100"><br>
      =<br>
      <img src="pic/phase-wave3.gif" width="100" height="100"></h1>
    <p>You can see that the two waveforms cancel each other out, leaving silence.
      This is called destructive interference.</p>
    <p>Believe it or not, but this occurs in many Soundblaster Live! and Audigy
      models, this is because there are two different codecs, one for the front,
      and one for the rear, and they are out of phase with each other.</p>
    <p>The subwoofer takes the 4 inputs, Front and Rear Left and Right, signals,
      and cuts off the lower bass end, and then adds it together to create the
      subwoofer output. </p>
    </font>
  <p><font face="arial">And as the outputs are out of phase, destructive interference
      affects the bass sound, although this does not cause total silence, there
      is a great reduction occuring along the bass line, making it sound &quot;Washed
      Out&quot;.</font></p>
  <p><font face="arial">Note: Some speakers designed especially for the Live!
      series cards automatically invert the phase of the rear outputs, so if
      the bass sounds perfect, you do not need to read this. </font></p>
  <p><font face="arial">To correct for this, we must use the DSP<br>
      <img src="pic/dsp-basic.gif" width="800" height="599">      <br>
      To learn the basics of DSP routing which you will need for this guide,
      see <a href="dsp.html">here</a>.</font></p>
    <p><font face="arial">What we need is a plugin that inverts the phase of
        a signal, this plugin is called &quot;Phase&quot; <br>
    <img src="pic/phase-dsp1.gif" width="800" height="600"> <br>
  Add the phase plugin to the DSP</font></p>
    <p><font face="arial"><img src="pic/phase-dsp2.gif" width="800" height="600"></font></p>
    <p><font face="arial">Now connect the &quot;sL&quot; and &quot;sR&quot; outputs from the Surrounder
        to the inputs in the Phase module<br>
        <img src="pic/phase-dsp3.gif" width="800" height="600"><br>
        And then connect the outputs of the Phase module to the &quot;Analog Rear
        Left&quot; and &quot;Analog Rear Right&quot; connectors on the Epilog.</font></p>
    <p><font face="arial">Make sure that if you connect &quot;sL' to the top input
        on the Phase module, that you connect the top output to &quot;Analog Rear
        Left&quot; on the epilog.<br>
    <img src="pic/phase-dsp4.gif" width="800" height="600"><br>
    Notice that once you connect the Phase module to the epilog, the wires that
    went directly from the Surrounder to the Epilog disappear as you replace
    the input.</font></p>
    <p><font face="arial">This should now fix the bass problem with 4.1 speakers </font></p>
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    <hr><font face="arial">
kX Guide &copy 2004 by Chris Stannard, a kX
user. All rights reserved.
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